Self-locking filter valve

Abstract

A lever actuated valve stem for control of liquid flow through a filtering device. The device is connectable to a source of impure liquids and includes a filter disposed between the inlet and the outlet of the device for the removal of the impurities. The valve stem is operable to direct fluid flow through the filter or to bypass the filter. The valve includes a lever slidably connected to a valve stem by means of a pin fixably attached to the lever and extending through a slot of the stem. The slot is arranged relative to the longitudinal axis of the stem to lock the pin and lever in either the filtering position or the bypass position.

The invention claimed is: 
     
       1. A device for filtering impure liquids comprising: liquid flow control means having an inlet and an outlet;   a filter removably mounted to said control means and having a first side in communication with said inlet and a second side communicating with said outlet;   passage means within said control means defining a liquid flow passage between said inlet and said outlet other than through said filter;   selectively operable valve means associated with said passage means and having a first position for permitting liquid flow between said inlet and said outlet through said passage means bypassing said filter and a second position for preventing liquid flow through said liquid flow passage whereby liquid flow is directed from said inlet through said filter to said outlet;   said valve means including a slidably mounted valve stem extendably through said liquid flow passage along a longitudinal axis to control liquid flow therein and a lever projecting externally of said control means for manually grasping and connecting means pivotally mounting said lever to said stem, said connecting means having a connecting axis between said lever and stem with said connecting axis movable between a first location on a first side of said longitudinal axis to a second location on a second side of said longitudinal axis opposite said first side as said valve means moves from said first position to said second position, said connecting means by location of said connecting axis together with said liquid pressure within said control means being operable to lock said lever and stem in said first position until manually moved and to lock said lever and stem in said position until manually moved;   said connecting means includes a slot and a pivot pin slidably associated together and with said stem and lever;   said slot terminates on opposite sides of said longitudinal axis;   said stem includes a proximal end with said slot located thereon;   said lever includes a fixed pivot axis with said pin offset therefrom extending into and slidable within said slot;   said control means includes a first stop and a second stop with said longitudinal axis extending therebetween,   said stem urged by liquid pressure within said control means releasably holds said lever against said first stop with said longitudinal axis positioned between said pin and said first stop, and holds said lever against said second stop when said longitudinal axis is positioned between said pin and said second stop.